1. Field of the Invention
The present invention relates to a displacement machine for compressible media.
2. Description of the Related Art
A displacement machine of this type is disclosed in the Swiss patent number 673 680. It has an approximately cylindrical housing with end walls and a peripheral outer wall. Integrally molded on the outer wall are connecting flanges which each have an inlet opening, are located diametrically opposite each other and are directed radially outward. Arranged in the housing are delivery spaces which lead in the manner of a spiral from the inlet openings to an outlet, which is located radially on the inside. A displacer cooperates with the delivery spaces and, during operation, together with the walls of the delivery spaces bounds a plurality of approximately sickle-shaped working spaces, which move from the inlets, through the delivery spaces, to the outlet, the volume of the working spaces being continuously reduced, because of the different curvature of the spiral shape, and the pressure of the operating medium being correspondingly increased thereby. Displacement machines of this type are distinguished by low-pulsation delivery of the gaseous operating medium, which consists of air or an air/fuel mixture, for example, and can therefore also advantageously be used for the purpose of charging internal combustion engines. In this case, the two inlet openings have to be combined, for example by means of a pipe system, in order to connect them to an upstream device, for example an air filter. This requires an undesirable amount of space, particularly in the radial direction.
A displacement machine having a single inlet opening that is arranged on an end wall of the housing is disclosed by DE-A-42 03 346. In the interior of the housing, a first delivery space leads from this inlet opening and, radially on the outside in relation to the latter, a channel leads away and leads to a second delivery space which is arranged to be offset by 180.degree. in relation to the first delivery space. Viewed in the radial direction, this embodiment also requires large external dimensions of the housing.